Answer:
B
Explanation:
The water will rise 1-2mm as observed by Tom.
Answer:
The density of water increases as the salinity increases. The density of seawater (salinity greater than 24.7) increases as temperature decreases at all temperatures above the freezing point. The density of seawater is increased by increasing pressure.
Explanation:
Answer:
The source of Calcium (Ca⁺⁺) for the skeletal muscle cells is the sarcoplasmic reticulum, the main store of intracellular Ca⁺⁺.
Explanation:
Calcium (Ca⁺⁺) is an ion that plays an important role in muscle contraction, a process that requires high cytoplasmic concentrations of this ion to promote myofibrillary activity.
The sarcoplasmic reticulum (SR) -equivalent to the endoplasmic smooth reticulum- is an organelle that regulates the contractile activity of skeletal muscle. The two terminal cisterns of the SR attach to the T-tube, forming a triad, which surrounds the myofibrilla.
Once the muscle cell receives the signal to contract, the Ca⁺⁺ channels are opened and allow Ca⁺⁺ to enter the cell, promoting the exit of this cation from the SR and increased its cytoplasmic levels. This stimulates muscle contraction.
Answer: A) Evolution or B) Natural Selection
Explanation: The fur of these bunnies change color with the seasons in order to better blend into their environment. This is an example of a species evolving to better survive!
However, this could also happen as a result of natural selection. Those who were able to better survive would pass on their genes for fur that changes with the seasons.
Answer: Cytotoxic T cells
Explanation:
A Cytotoxic T cell is a cell whose activation is mainly aimed at destroying cells that are infected by virus. It is a type of white blood cells that destroys cancerous cells or cells that are impaired especially by viruses. A Cytotoxic cell is also known as T-killer cells, Cytolytic T cells, T lymphocyte.
Cytotoxic T cells destroy target cells by prearranged apoptoses.
